Most hand tools are based on designs which have been around for decades or centuries and can in most cases benefit from improvements in their design made using modern ergonomic and biomechanical design and measurement techniques. Ergonomic hand tools are generally designed to minimize the effort and strain on the human body while maximizing their efficiency. Many diseases such as Carpal Tunnel Syndrome, Tendinitis, Bursitis, and Tenosynovitis can be caused by repeated use of poorly designed tools. It is known that hand tools should be designed to limit the motion of the wrist to the middle third of the range of motion to help reduce the risk of these diseases. Ergonomic hand tools having bent handles to improve the efficiency of the tool and limit the range of motion of the wrist have been known for some time. One example of which is the Bennett handle which provides a curved handle grip which angles vertically downwards into the hand and follows the line between the index finger and the ball of the thumb. This handle when employed for example on a hammer reduces the range of motion of the wrist and improves the striking angle of the hammer. The Bennett handle however does not bring the tool into alignment with the forearm. This requires that the individual using the tool angle their wrist slightly to bring the tool into alignment with the forearm during use. This can result in repetitive strain injuries if the tool is used often or for long periods of time. Most hand tools have a handle which is substantially straight. This tends to result in the tool head falling in the line of sight of the individual 5 using the tool and obscuring the work area.
Canadian Patent 2,208,951 discloses a handle design with improved ergonomics in view of the above prior handle designs, however the tool head is not suitably aligned with the offset gripping portion for all applications, accordingly, the applications of the handle to a hammer head are limited.